In a three-phase balanced system, a delta-connected source supplies power to a wye-connected load. If the line impedance is $0.2+j 0.4 \Omega,$ the load impedance is $3+j 2 \Omega,$ and the source phase voltage $\mathbf{V}_{a b}=208 / 10^{\circ} \mathrm{V} \mathrm{rms}$, find the magnitude of the line voltage at the load.